Osteoporos Int DOI 10.1007/s00198-015-3163-5
ORIGINAL ARTICLE
Improvement of spinal alignment and quality of life after corrective surgery for spinal kyphosis in patients with osteoporosis: a comparative study with non-operated patients N. Miyakoshi 1 & M. Hongo 1 & T. Kobayashi 2 & T. Abe 2 & E. Abe 2 & Y. Shimada 1
Received: 14 April 2015 / Accepted: 1 May 2015 # International Osteoporosis Foundation and National Osteoporosis Foundation 2015
Abstract Summary This study evaluated changes in spinal alignment and quality of life (QOL) after corrective spinal surgery for patients with postmenopausal osteoporosis and spinal kyphosis. Spinal global alignment and QOL were significantly improved after corrective spinal surgery but did not reach the level of non-operated controls. Introduction With the increased aging of society, the demand for corrective spinal instrumentation for spinal kyphosis in osteoporotic patients is increasing. However, previous studies have not focused on the improvement of quality of life (QOL) after corrective spinal surgery in patients with osteoporosis, compared to non-operated control patients. The purposes of this study were thus to evaluate changes in spinal alignment and QOL after corrective spinal instrumentation for patients with osteoporosis and spinal kyphosis and to compare these results with non-operated patients. Methods Participants comprised 39 patients with postmenopausal osteoporosis ≥50 years old who underwent corrective spinal surgery using multilevel posterior lumbar interbody fusion (PLIF) for symptomatic thoracolumbar or lumbar kyphosis, and 82 age-matched patients with postmenopausal osteoporosis without prevalent vertebral fractures. Spinopelvic parameters were evaluated with standing lateral spine radiography, and QOL was evaluated with the Japanese
* N. Miyakoshi [email protected] 1
Department of Orthopedic Surgery, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
2
Department of Orthopedic Surgery, Akita Kousei Medical Center, 1-1-1 Iijima-Nishifukuro, Akita 011-0948, Japan
Osteoporosis QOL Questionnaire (JOQOL), SF-36, and Roland-Morris Disability Questionnaire (RDQ). Results Lumbar kyphosis angle, sagittal vertical axis, and pelvic tilt were significantly improved postoperatively. QOL evaluated with all three questionnaires also significantly improved after 6 months postoperatively, particularly in domain and subscale scores for pain and general/mental health. However, these radiographic parameters, total JOQOL score, SF36 physical component summary score, and RDQ score were significantly inferior compared with non-operated controls. Conclusions The results indicate that spinal global alignment and QOL were significantly improved after corrective spinal surgery using multilevel PLIF for patients with osteoporosis and spinal kyphosis but did not reach the level of non-operated controls. Keywords Kyphosis . Osteoporosis . Posterior lumbar interbody fusion . Quality of life . Spinal instrumentation
Introduction Osteoporosis is a disorder that generally affects the biomechanical competence of bone and leads to an increased risk of fractures, with older female patients as the most severely affected population. Osteoporotic patients frequently suffer spinal kyphosis; this often results from vertebral fractures, the most common clinical manifestation of the disease, but is also related to weakness of the back extensor muscles [1, 2] and intervertebral disc degeneration. Spinal kyphosis in patients with osteoporosis causes chronic back pain and significant functional impairments in activities of daily living (ADL) [3–6]. These functional impairments by spinal kyphosis also influence the quality of life (QOL) in patients with osteoporosis [5–8].
Osteoporos Int
With the increased aging of society worldwide, the demand for corrective spinal instrumentation for spinal kyphosis is increasing even for osteoporotic elderly patients. In cases of adult spinal deformity, recent studies have shown that positive sagittal plane imbalance is directly associated with decreased QOL outcome scores [9–11], and postoperative improvement in sagittal plane alignment has been shown to significantly improve patient outcomes [10, 12]. However, no studies specifically focusing on the improvement of QOL after corrective spinal surgery in patients with osteoporosis and spinal kyphosis have been reported. In addition, we have been unable to determine whether the postoperative improvement of QOL is comparable with common osteoporosis patients without prevalent vertebral fractures, because no studies have reported the comparison of surgical results with non-operated control patients with osteoporosis. The purposes of this study were thus to evaluate changes in spinal alignment and QOL after corrective spinal instrumentation for patients with postmenopausal osteoporosis and thoracolumbar or lumbar kyphosis and to compare these results with non-operated patients with postmenopausal osteoporosis without prevalent vertebral fractures.
Materials and methods Patients Subjects comprised 39 consecutive patients with postmenopausal osteoporosis ≥50 years old who underwent corrective spinal surgery for symptomatic thoracolumbar or lumbar kyphosis (surgery group), and 82 consecutive age-matched patients with postmenopausal osteoporosis without prevalent vertebral fractures who had visited our outpatient clinics for the treatment of osteoporosis as non-operated controls (control group). The recruitment period was the same for patients in both groups, from January 2011 to December 2013. In the surgery group, 7 patients (18 %) showed vertebral fractures (4 patients had one fracture, and 3 patients had 2 fractures). Osteoporosis was diagnosed according to the criteria proposed by the Japanese Society for Bone and Mineral Research, as described in the Japanese 2011 guidelines for the prevention and treatment of osteoporosis [13]. Briefly, osteoporosis was diagnosed in patients with (1) any fragility fractures or (2) bone mineral density (BMD) level less than 70 % of the young adult mean or radiographic osteopenia of the spine. All patients had been prescribed oral bisphosphonates (35 mg/week of alendronate or 17.5 mg/week of risedronate) for the treatment of osteoporosis. Lateral spine radiographs to evaluate global spinal sagittal alignment and questionnaires for QOL were obtained from each patient. Patients undergoing surgery were examined before surgery and after 6 months postoperatively, and control patients without surgery were examined at the time of
enrollment. Patients undergoing surgery were followed up prospectively, and none dropped out during follow-up. Exclusion criteria were as follows: (1) history of metabolic bone disease other than primary osteoporosis or history of malignancy; (2) history of spinal surgery before inclusion; (3) spinal scoliosis; (4) chronic glucocorticoid use; or (5) documented fresh fractures (in vertebrae and extremities) within the last 6 months. An informed consent was obtained from all patients at the time of enrollment. Corrective spinal surgery The indications for corrective spinal surgery were osteoporosis with rigid thoracolumbar or lumbar kyphosis and impaired QOL caused mainly by intolerable back and/or low back pain due to spinal imbalance that was not adequately controlled by comprehensive conservative treatment (i.e., pharmacotherapy, physiotherapy, braces, and trigger point block). However, because of the high invasiveness of the surgery, in principle, we applied corrective spinal surgery for healthy osteoporotic individuals without serious comorbidities. The majority of operated patients in this study were agriculturists who had a history of hard manual labor before retirement. All operated patients underwent posterior-approach corrective fusion using a posterior lumbar interbody fusion (PLIF) technique for multiple levels (Fig. 1). The upper end of the fusion ranged from T4 to L2, and the lower end was L5 or S1 based on the level of kyphosis and the magnitude of spinal curvature in the individual. For all 39 operated patients, the mean number of fused levels was 6.6 (range, 3–13). The multilevel PLIF technique provides sufficient spinal correction [14]. Because PLIF can be applied even if the patient has mild vertebral deformity, most cases in this study underwent spinal correction using this technique alone. However, in some patients with severely collapsed vertebrae, the vertebrae were partially resected and replaced with large, rectangular, parallelepiped cages (REC cages) and autograft bone. This technique is a modification of the PLIF technique and was termed Bposterior-approach vertebral replacement with REC cages^ (PAVREC) [15]. PAVREC was applied as a part of spinal correction combined with multilevel PLIF. Because the present study did not aim to discuss surgical invasiveness and complications, parameters regarding surgical invasiveness and complications were not included. Operative invasiveness (i.e., surgical time and blood loss) and perioperative complications of multilevel PLIF have been described elsewhere [16]. Although these surgeries seemed highly invasive, we did not encounter any critical complications [16]. Radiologic measurements On standing lateral total spine x-ray, the following spinopelvic parameters for global spinal sagittal alignment were
Osteoporos Int
QOL evaluation QOL was evaluated with the Japanese Osteoporosis QOL Questionnaire (JOQOL) [17, 18], the Medical Outcomes Study Short Form 36 (SF-36) [19, 20], and the RolandMorris Disability Questionnaire (RDQ) [21, 22]. JOQOL was developed based on the Osteoporosis Assessment Questionnaire (OPAQ) [23] and Qualeffo-41 [24], with modification according to the Japanese lifestyle. JOQOL contains 38 items in six domains: pain (back/low back pain) (5 items, 20 points); ADL (16 items, 64 points); leisure and social activities (5 items, 20 points); general health perception (3 items, 12 points); posture and figure (4 items, 16 points); and fear of falling and mental factors (5 items, 20 points). Scores for each item range from 0 to 4, with a maximum possible score of 152. In JOQOL and SF-36, a higher score indicates a higher level of QOL. Conversely, a higher RDQ score indicates a lower QOL. Statistical analyses
Fig. 1 Preoperative (a) and postoperative (b) standing lateral radiographs of a 73-year-old woman with prevalent L3 osteoporotic vertebral fracture and lumbar kyphosis who underwent multilevel posterior lumbar interbody fusion (PLIF) combined with posterior instrumentation. Spinal alignment was improved after surgery
measured: thoracic kyphosis angle (TKA), angle between the upper endplate of T4 and the lower endplate of T12; lumbar lordosis angle (LLA), angle between the upper endplate of L1 and the upper endplate of S1; sagittal vertical axis (SVA); pelvic tilt (PT); and pelvic incidence (PI). TKA and LLA were measured using the Cobb angle method. SVA is defined as the horizontal offset from the posterosuperior corner of S1 to the vertebral midbody of C7 [12]. Increased SVA means the trunk is inclined anteriorly (stooped trunk). PT is defined as the angle between the vertical and the line through the midpoint of the sacral plate to the femoral head axis [12]. It has commonly been recognized as a compensatory mechanism that when the trunk is inclined anteriorly (e.g., increased kyphosis), a subject will try his/her best to maintain an economic posture and keep the spine balanced (i.e., bring the spine over the pelvis) [12]. One way to maintain this spinopelvic alignment is to retrovert the pelvis (increase of PT) [12]. PI is defined as the angle between the perpendicular to the upper sacral endplate at its midpoint and the line connecting this point to the femoral head axis [12]. PI is a morphological parameter of primary importance commonly used to define spinopelvic morphotypes [12]. In all patients, BMD of the proximal femur was measured with dual-energy x-ray absorptiometry (QDR 4500A; Hologic, Waltham, MA, USA) at the time of enrollment.
All data are expressed as mean±standard deviation (SD). All statistical analyses were performed using StatView statistical software (SAS Institute, Cary, NC, USA). Differences between pre- and postoperative values were evaluated using repeated-measures one-way analysis of variance and Fisher’s protected least-significant difference as a post-hoc test. Differences between operated and non-operated groups were evaluated with the unpaired t test. Values of p
ORIGINAL ARTICLE
Improvement of spinal alignment and quality of life after corrective surgery for spinal kyphosis in patients with osteoporosis: a comparative study with non-operated patients N. Miyakoshi 1 & M. Hongo 1 & T. Kobayashi 2 & T. Abe 2 & E. Abe 2 & Y. Shimada 1
Received: 14 April 2015 / Accepted: 1 May 2015 # International Osteoporosis Foundation and National Osteoporosis Foundation 2015
Abstract Summary This study evaluated changes in spinal alignment and quality of life (QOL) after corrective spinal surgery for patients with postmenopausal osteoporosis and spinal kyphosis. Spinal global alignment and QOL were significantly improved after corrective spinal surgery but did not reach the level of non-operated controls. Introduction With the increased aging of society, the demand for corrective spinal instrumentation for spinal kyphosis in osteoporotic patients is increasing. However, previous studies have not focused on the improvement of quality of life (QOL) after corrective spinal surgery in patients with osteoporosis, compared to non-operated control patients. The purposes of this study were thus to evaluate changes in spinal alignment and QOL after corrective spinal instrumentation for patients with osteoporosis and spinal kyphosis and to compare these results with non-operated patients. Methods Participants comprised 39 patients with postmenopausal osteoporosis ≥50 years old who underwent corrective spinal surgery using multilevel posterior lumbar interbody fusion (PLIF) for symptomatic thoracolumbar or lumbar kyphosis, and 82 age-matched patients with postmenopausal osteoporosis without prevalent vertebral fractures. Spinopelvic parameters were evaluated with standing lateral spine radiography, and QOL was evaluated with the Japanese
* N. Miyakoshi [email protected] 1
Department of Orthopedic Surgery, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
2
Department of Orthopedic Surgery, Akita Kousei Medical Center, 1-1-1 Iijima-Nishifukuro, Akita 011-0948, Japan
Osteoporosis QOL Questionnaire (JOQOL), SF-36, and Roland-Morris Disability Questionnaire (RDQ). Results Lumbar kyphosis angle, sagittal vertical axis, and pelvic tilt were significantly improved postoperatively. QOL evaluated with all three questionnaires also significantly improved after 6 months postoperatively, particularly in domain and subscale scores for pain and general/mental health. However, these radiographic parameters, total JOQOL score, SF36 physical component summary score, and RDQ score were significantly inferior compared with non-operated controls. Conclusions The results indicate that spinal global alignment and QOL were significantly improved after corrective spinal surgery using multilevel PLIF for patients with osteoporosis and spinal kyphosis but did not reach the level of non-operated controls. Keywords Kyphosis . Osteoporosis . Posterior lumbar interbody fusion . Quality of life . Spinal instrumentation
Introduction Osteoporosis is a disorder that generally affects the biomechanical competence of bone and leads to an increased risk of fractures, with older female patients as the most severely affected population. Osteoporotic patients frequently suffer spinal kyphosis; this often results from vertebral fractures, the most common clinical manifestation of the disease, but is also related to weakness of the back extensor muscles [1, 2] and intervertebral disc degeneration. Spinal kyphosis in patients with osteoporosis causes chronic back pain and significant functional impairments in activities of daily living (ADL) [3–6]. These functional impairments by spinal kyphosis also influence the quality of life (QOL) in patients with osteoporosis [5–8].
Osteoporos Int
With the increased aging of society worldwide, the demand for corrective spinal instrumentation for spinal kyphosis is increasing even for osteoporotic elderly patients. In cases of adult spinal deformity, recent studies have shown that positive sagittal plane imbalance is directly associated with decreased QOL outcome scores [9–11], and postoperative improvement in sagittal plane alignment has been shown to significantly improve patient outcomes [10, 12]. However, no studies specifically focusing on the improvement of QOL after corrective spinal surgery in patients with osteoporosis and spinal kyphosis have been reported. In addition, we have been unable to determine whether the postoperative improvement of QOL is comparable with common osteoporosis patients without prevalent vertebral fractures, because no studies have reported the comparison of surgical results with non-operated control patients with osteoporosis. The purposes of this study were thus to evaluate changes in spinal alignment and QOL after corrective spinal instrumentation for patients with postmenopausal osteoporosis and thoracolumbar or lumbar kyphosis and to compare these results with non-operated patients with postmenopausal osteoporosis without prevalent vertebral fractures.
Materials and methods Patients Subjects comprised 39 consecutive patients with postmenopausal osteoporosis ≥50 years old who underwent corrective spinal surgery for symptomatic thoracolumbar or lumbar kyphosis (surgery group), and 82 consecutive age-matched patients with postmenopausal osteoporosis without prevalent vertebral fractures who had visited our outpatient clinics for the treatment of osteoporosis as non-operated controls (control group). The recruitment period was the same for patients in both groups, from January 2011 to December 2013. In the surgery group, 7 patients (18 %) showed vertebral fractures (4 patients had one fracture, and 3 patients had 2 fractures). Osteoporosis was diagnosed according to the criteria proposed by the Japanese Society for Bone and Mineral Research, as described in the Japanese 2011 guidelines for the prevention and treatment of osteoporosis [13]. Briefly, osteoporosis was diagnosed in patients with (1) any fragility fractures or (2) bone mineral density (BMD) level less than 70 % of the young adult mean or radiographic osteopenia of the spine. All patients had been prescribed oral bisphosphonates (35 mg/week of alendronate or 17.5 mg/week of risedronate) for the treatment of osteoporosis. Lateral spine radiographs to evaluate global spinal sagittal alignment and questionnaires for QOL were obtained from each patient. Patients undergoing surgery were examined before surgery and after 6 months postoperatively, and control patients without surgery were examined at the time of
enrollment. Patients undergoing surgery were followed up prospectively, and none dropped out during follow-up. Exclusion criteria were as follows: (1) history of metabolic bone disease other than primary osteoporosis or history of malignancy; (2) history of spinal surgery before inclusion; (3) spinal scoliosis; (4) chronic glucocorticoid use; or (5) documented fresh fractures (in vertebrae and extremities) within the last 6 months. An informed consent was obtained from all patients at the time of enrollment. Corrective spinal surgery The indications for corrective spinal surgery were osteoporosis with rigid thoracolumbar or lumbar kyphosis and impaired QOL caused mainly by intolerable back and/or low back pain due to spinal imbalance that was not adequately controlled by comprehensive conservative treatment (i.e., pharmacotherapy, physiotherapy, braces, and trigger point block). However, because of the high invasiveness of the surgery, in principle, we applied corrective spinal surgery for healthy osteoporotic individuals without serious comorbidities. The majority of operated patients in this study were agriculturists who had a history of hard manual labor before retirement. All operated patients underwent posterior-approach corrective fusion using a posterior lumbar interbody fusion (PLIF) technique for multiple levels (Fig. 1). The upper end of the fusion ranged from T4 to L2, and the lower end was L5 or S1 based on the level of kyphosis and the magnitude of spinal curvature in the individual. For all 39 operated patients, the mean number of fused levels was 6.6 (range, 3–13). The multilevel PLIF technique provides sufficient spinal correction [14]. Because PLIF can be applied even if the patient has mild vertebral deformity, most cases in this study underwent spinal correction using this technique alone. However, in some patients with severely collapsed vertebrae, the vertebrae were partially resected and replaced with large, rectangular, parallelepiped cages (REC cages) and autograft bone. This technique is a modification of the PLIF technique and was termed Bposterior-approach vertebral replacement with REC cages^ (PAVREC) [15]. PAVREC was applied as a part of spinal correction combined with multilevel PLIF. Because the present study did not aim to discuss surgical invasiveness and complications, parameters regarding surgical invasiveness and complications were not included. Operative invasiveness (i.e., surgical time and blood loss) and perioperative complications of multilevel PLIF have been described elsewhere [16]. Although these surgeries seemed highly invasive, we did not encounter any critical complications [16]. Radiologic measurements On standing lateral total spine x-ray, the following spinopelvic parameters for global spinal sagittal alignment were
Osteoporos Int
QOL evaluation QOL was evaluated with the Japanese Osteoporosis QOL Questionnaire (JOQOL) [17, 18], the Medical Outcomes Study Short Form 36 (SF-36) [19, 20], and the RolandMorris Disability Questionnaire (RDQ) [21, 22]. JOQOL was developed based on the Osteoporosis Assessment Questionnaire (OPAQ) [23] and Qualeffo-41 [24], with modification according to the Japanese lifestyle. JOQOL contains 38 items in six domains: pain (back/low back pain) (5 items, 20 points); ADL (16 items, 64 points); leisure and social activities (5 items, 20 points); general health perception (3 items, 12 points); posture and figure (4 items, 16 points); and fear of falling and mental factors (5 items, 20 points). Scores for each item range from 0 to 4, with a maximum possible score of 152. In JOQOL and SF-36, a higher score indicates a higher level of QOL. Conversely, a higher RDQ score indicates a lower QOL. Statistical analyses
Fig. 1 Preoperative (a) and postoperative (b) standing lateral radiographs of a 73-year-old woman with prevalent L3 osteoporotic vertebral fracture and lumbar kyphosis who underwent multilevel posterior lumbar interbody fusion (PLIF) combined with posterior instrumentation. Spinal alignment was improved after surgery
measured: thoracic kyphosis angle (TKA), angle between the upper endplate of T4 and the lower endplate of T12; lumbar lordosis angle (LLA), angle between the upper endplate of L1 and the upper endplate of S1; sagittal vertical axis (SVA); pelvic tilt (PT); and pelvic incidence (PI). TKA and LLA were measured using the Cobb angle method. SVA is defined as the horizontal offset from the posterosuperior corner of S1 to the vertebral midbody of C7 [12]. Increased SVA means the trunk is inclined anteriorly (stooped trunk). PT is defined as the angle between the vertical and the line through the midpoint of the sacral plate to the femoral head axis [12]. It has commonly been recognized as a compensatory mechanism that when the trunk is inclined anteriorly (e.g., increased kyphosis), a subject will try his/her best to maintain an economic posture and keep the spine balanced (i.e., bring the spine over the pelvis) [12]. One way to maintain this spinopelvic alignment is to retrovert the pelvis (increase of PT) [12]. PI is defined as the angle between the perpendicular to the upper sacral endplate at its midpoint and the line connecting this point to the femoral head axis [12]. PI is a morphological parameter of primary importance commonly used to define spinopelvic morphotypes [12]. In all patients, BMD of the proximal femur was measured with dual-energy x-ray absorptiometry (QDR 4500A; Hologic, Waltham, MA, USA) at the time of enrollment.
All data are expressed as mean±standard deviation (SD). All statistical analyses were performed using StatView statistical software (SAS Institute, Cary, NC, USA). Differences between pre- and postoperative values were evaluated using repeated-measures one-way analysis of variance and Fisher’s protected least-significant difference as a post-hoc test. Differences between operated and non-operated groups were evaluated with the unpaired t test. Values of p
